The licence EUPL v.1.0 was write in English and had been made by the European Union official translations into French and German.

Web address where you can download these texts:
http://ec.europa.eu/idabc/en/document/6523

The translation into Spanish offered on the bellow link is a non official translation made by Ignacio Botella Alarcón whose only function is to facilitate the understanding of the original license to dose spanish speakers, but for legal matters you should refer to official translation on the above link.

Licencia EUPL v.1.0 en español (in Spanish)

EUPL © European Community 2007